Array panel for liquid crystal display device and method of manufacturing the same

ABSTRACT

An array panel for a liquid crystal display device includes a substrate, a gate line and a gate electrode on the substrate, wherein the gate line is connected to the gate electrode, a gate insulating layer on the gate line and the gate electrode, an active layer on the gate insulating layer, an ohmic contact layer on the active layer, a data line, a source electrode, and a drain electrode on the ohmic contact layer, wherein the data line, the source electrode, and the drain electrode are formed of molybdenum, a passivation layer on the data line, the source and drain electrodes, and a pixel electrode on the passivation layer, wherein the ohmic contact layer has the same shape as the data line, the source, and drain electrodes, and the active layer has the same shape as the data line, and the source electrode, and the drain electrode except for a channel area between the source electrode and the drain electrode, and the channel area has a “U” shape.

This application is a divisional of U.S. patent application Ser. No.10/141,085, filed May 9, 2002, which is hereby incorporated byreference. This application also claims the benefit of the Korean PatentApplication No. P2001-065911 filed on Oct. 25, 2001, which is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display (LCD) deviceand more particularly, to an array panel for a liquid crystal displaydevice and a method of manufacturing the same.

2. Discussion of the Related Art

A flat panel display device has been widely used because it is thin andlight in weight and requires low power consumption. The flat paneldisplay device may be classified into two types by light emission. Oneis a light-emitting display device that emits light to display imagesand the other is a light-receiving display device that uses an externallight source to display images. Plasma display panels (PDPs), fieldemission display (FED) devices and electro luminescence (EL) displaydevices are examples of the light-emitting display devices and a liquidcrystal display (LCD) device is an example of the light-receivingdisplay device. The liquid crystal display device has been widely usedfor notebook computers and desktop monitors, etc. because of itssuperior resolution, color image display, and quality of displayedimages.

Generally, the liquid crystal display (LCD) device has upper and lowersubstrates, which are spaced apart and facing into each other.Electrodes formed on the substrates are facing each other. A liquidcrystal is interposed between the upper substrate and the lowersubstrate. A voltage is applied to the liquid crystal through theelectrodes of each substrate, and thus an alignment of the liquidcrystal molecules is changed according the applied voltage to displayimages. Because the liquid crystal display device does not emit light asdescribed above, it needs a light source to display images. Accordingly,the liquid crystal display device has a backlight behind a liquidcrystal panel as a light source. An amount of light incident from thebacklight is controlled according the alignment of the liquid crystalmolecules to display images.

An active matrix LCD device, which has pixels in a matrix type, has beenwidely used because of high resolution and fast moving images. An arraypanel of the active matrix LCD device includes a plurality of thin filmtransistors (TFTs) and a plurality of pixel electrodes, each of whichconnects with each of TFTs.

The array panel for a conventional active matrix liquid crystal displaydevice will be described hereinafter in detail with reference to FIGS. 1and 2.

FIG. 1 is a plane view of an array panel for a conventional LCD device,and FIG. 2 is a cross-sectional view along line II-II of FIG. 1. InFIGS. 1 and 2, the array panel includes a transparent substrate 10, anda gate line 21 and a gate electrode 22 are formed on the substrate 10.The gate line 21 is extended horizontally and the gate electrode 22 isconnected to the gate line 21. A gate insulating layer 30 covers thegate line 21 and the gate electrode 22. An active layer 41 and an ohmiccontact layer 51 and 52 are formed on the gate insulating layer 30 inthis order. A data line 61, a source electrode 62, and a drain electrode63 are formed on the ohmic contact layer 51 and 52. Also, a capacitorelectrode 65, which is made of the same material as the data line 61, isformed on the gate insulator 30. The data line 61 is perpendicular tothe gate line 21, and the source electrode 62 is connected to the dataline 61. The source and drain electrodes 62 and 63 are spaced apart fromeach other on the gate electrode 22. The capacitor electrode 65 overlapsa portion of the gate line 21, and then a storage capacitor is obtainedby forming the capacitor electrode 65 and the overlapped gate line 21.

A passivation layer 70 covers the data line 61, the source electrode 62,the drain electrode 63, and the capacitor electrode 65. The passivationlayer 70 has a first contact hole 71 and a second contact hole 72 thatexpose the drain electrode 63 and the capacitor electrode 65,respectively.

A pixel electrode 81 is formed on the passivation layer 70. The pixelelectrode 81 is disposed at the pixel area where the gate line 21 andthe data line 61 are crossed to each other. Also, the pixel electrode 81is connected to the drain electrode 62 and the capacitor electrode 65through the first and second contact hole 71 and 72, respectively.

FIGS. 3A to 3E illustrate a manufacturing process of an array panel forthe conventional LCD device, and are cross-sectional views correspondingto line II-II of FIG. 1.

FIG. 3A shows the first step of manufacturing the array panel for theconventional LCD device. In FIG. 3A, a gate line 21 and a gate electrode22 are formed on a substrate 10 by depositing a metal material on thesubstrate 10 and patterning the metal material by the first mask.

FIG. 3B illustrates the next step of manufacturing the array panel forthe conventional LCD device. In FIG. 3B, a gate insulating layer 30, anamorphous silicon layer and an doped amorphous silicon layer aredeposited on the substrate 10 including the gate line 21. The amorphoussilicon layer and the doped amorphous silicon layer are etched in aphotolithography process using the second mask. Then, an active layer 41and a doped semiconductor layer 53 are formed thereon.

FIG. 3C shows the step of forming a data line of the array panel for theconventional LCD device. In FIG. 3C, a metal layer is deposited on thesubstrate 10 including the active layer 41 and the doped semiconductorlayer 53, and patterned by the third mask. Therefore, a data line 61(shown in FIG. 1), a source electrode 62, a drain electrode 63, and acapacitor electrode 65 are formed thereon. Next, the doped semiconductorlayer 53, which is exposed between the source electrode 62 and the drainelectrode 63, is etched. An ohmic contact layer 51 and 52 is thencompleted in this step.

FIG. 3D shows the step of forming a passivation layer of the array panelfor the conventional LCD device. In FIG. 3D, a passivation layer 70 isformed to cover the data line 61, the source electrode 62, the drainelectrode 63, and the capacitor electrode 65. And, the passivation layer70 is etched using the fourth mask. Therefore, the passivation layer 70has a first contact hole 71 and a second contact hole 72. The firstcontact hole 71 and the second contact hole 72 expose the drainelectrode 63 and the capacitor electrode 65, respectively.

FIG. 3E illustrates the step of forming a pixel electrode of the arraypanel for the conventional LCD device. In FIG. 3E, a transparentconductive material is deposited on the passivation layer 70 and etchedusing the fifth mask, and then a pixel electrode 81 is formed. The pixelelectrode 81 is connected to the drain electrode 63 and the capacitorelectrode 65 through the first and second contact holes 71 and 72,respectively.

As described above, the array panel for the conventional LCD device isfabricated through the photolithography processes using five masks. Thephotolithography process includes several steps of cleaning, coating aphoto-resist layer, exposing through a mask, developing the photo-resistlayer, and etching. Therefore, fabricating time, costs, and failure maybe decreased by reducing the number of the photolithography process.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an array panel for aliquid crystal display device and a method of manufacturing the samethat substantially obviates one or more of problems due to limitationsand disadvantages of the related art.

Another object of the present invention is to provide an array panel fora liquid crystal display device that is fabricated in a short period oftime with a lower cost.

Another object of the present invention is to provide a manufacturingmethod of the array panel that increases productivity because of theshorter processes and the lower cost.

Additional features and advantages of the invention will be set forth inthe description which follows and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, an arraypanel for a liquid crystal display device includes a substrate, a gateline and a gate electrode on the substrate, wherein the gate line isconnected to the gate electrode, a gate insulating layer on the gateline and the gate electrode, an active layer on the gate insulatinglayer, an ohmic contact layer on the active layer, a data line, a sourceelectrode, and a drain electrode on the ohmic contact layer, wherein thedata line, the source electrode, and the drain electrode are formed ofmolybdenum, a passivation layer on the data line, the source electrode,and the drain electrode, and a pixel electrode on the passivation layer,wherein the ohmic contact layer has the same shape as the data line, thesource electrode, and the drain electrode, and the active layer has thesame shape as the data line, the source electrode, and the drainelectrode except for a channel area between the source electrode and thedrain electrode, and the channel area has a “U” shape.

In another aspect of the present invention, a method of manufacturing anarray panel for a liquid crystal display device includes forming a gateline and a gate electrode on a substrate, forming a gate insulatinglayer on the gate line and the gate electrode, forming an active layeron the gate insulating layer, forming ohmic contact layer on the activelayer, forming a data line, a source electrode, and a drain electrode onthe ohmic contact layer, wherein the data line, the source electrode,and the drain electrode are formed of molybdenum, forming a passivationlayer on the data line, the source electrode, and the drain electrode,and forming a pixel electrode on the passivation layer, wherein theohmic contact layer has the same shape as the data line, the sourceelectrode, and the drain electrode, and the active layer has the sameshape as the data line, the source electrode, and the drain electrodeexcept for a channel area between the source electrode and the drainelectrode, and the channel area has a “U” shape.

In another aspect of the present invention, a method of manufacturing anarray panel for a liquid crystal display device includes steps offorming a gate line and a gate electrode on a substrate using a firstmask, forming a gate insulating layer, an amorphous silicon layer, adoped amorphous silicon layer, and a metal layer on the substrate inthis order, forming an active layer, an ohmic contact layer, a dataline, a source electrode, and a drain electrode using a second mask,forming a passivation layer using a third mask, and forming a pixelelectrode on the passivation layer using a fourth mask, wherein achannel area between the source electrode and the drain electrode has a“U” shape.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiments of the invention andtogether with the description serve to explain the principle of theinvention.

In the drawings:

FIG. 1 is a plane view of an array panel for a conventional liquidcrystal display device;

FIG. 2 is a cross-sectional view along line II-II of FIG. 1;

FIGS. 3A to 3E are cross-sectional views illustrating a manufacturingprocess of an array panel for the conventional liquid crystal displaydevice;

FIG. 4 is a plane view of an array panel for a liquid crystal displaydevice according to the present invention;

FIG. 5 is a cross-sectional view along line V-V of FIG. 4;

FIGS. 6A and 6B, FIGS. 7A to 7E, and FIGS. 8A and 8B illustrate amanufacturing process of an array panel for a liquid crystal displaydevice according to the present invention; and

FIG. 9 is showing a mask shape according to the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to the illustrated embodiments ofthe present invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.

FIG. 4 is a plane view of an array panel for a liquid crystal displaydevice according to the present invention, and FIG. 5 is across-sectional view along line V-V of FIG. 4.

As shown in the FIGS. 4 and 5, a gate line 121, a gate electrode 122, afirst shielding pattern 124 (i.e., a first light shielding pattern) anda second shielding pattern 125 (i.e., a second light shielding pattern)are formed on a substrate 110. The gate line 121 is extendedhorizontally, and the gate electrode 122 is connected to the gate line121. The first and second shielding patterns 124 and 125 are extendedvertically between the gate lines 121. The first shielding pattern 124is separated from others while the second shielding pattern 125 isconnected to the gate line 121. The first shielding pattern 124 has twoprojecting parts facing towards the second shielding pattern,125 at bothends. The gate line 121 also has a concave part at the regioncorresponding to the gate electrode 122.

A gate insulating layer 130 is formed to cover the gate line 121, thegate electrode 122, the first shielding pattern 124, and the secondshielding pattern 125.

An active layer 141 is formed on the gate insulating layer 130 and theactive layer 141 is disposed on the gate electrode 122. Next, an ohmiccontact layer 151 and 152 is formed on the active layer 141.

A data line 161, a source electrode 162, and a drain electrode 163 areformed on the ohmic contact layer 151 and 152 by depositing andpatterning a molybdenum (Mo) layer, for example. The data line 161 isextended vertically and defines the pixel region “P” by intersecting thegate line 122. The source electrode 162 is connected to the data line161 and is a “U” shape. The “U” shape is substantially completelysymmetrical. The drain electrode 163 is separated from the sourceelectrode 162 and has first and second parts. The first part is extendedhorizontally, while the second part is extended from the first part, andfacing toward the pixel region “P”. One end of the first part issurrounded by the source electrode 162, and thus a channel of a thinfilm transistor, which is defined as the active layer 141 disposedbetween the source electrode 162 and the drain electrode 163, has a “U”shape.

Meantime, the second part of the drain electrode 162 has protrusions inorder to expand the contacted area to a pixel electrode to be formedlater. Also, the data line 161 overlaps the projection parts of thefirst shielding pattern 124. When the data line 161 is disconnected, thedata line 161 is short-circuited with the projection portions of thefirst shielding pattern 124 by a laser beam. Therefore, even if the dataline 161 is disconnected, a signal can be transmitted through the firstshielding pattern 124.

Here, the ohmic contact layer 151 and 152 has the same shape as the dataline 161, the source electrode 162, and the drain electrode 163, whilethe active layer 141 has the same shape as the data line 161, the sourceelectrode 162, and the drain electrode 163 except for the channelregion.

Next, a passivation layer 170 is formed to cover the data line 161, thesource electrode 162, and the drain electrode 163. The passivation layer170 has a contact hole 171 exposing the drain electrode 163 in the gateinsulating layer 130. The contact hole 171 also exposes one sidewall ofthe drain electrode 163.

A pixel electrode 181 is formed on the passivation layer 170. The pixelelectrode 181 is disposed in the pixel region “P” and is made of atransparent conductive material. The pixel electrode 181 is connected tothe drain electrode 163 through the contact hole 171, and overlaps theprevious gate line 121 to form a storage capacitor. Also, the pixelelectrode 181 overlaps the first shielding pattern 124, the secondshielding pattern 125, and the first part of the drain electrode 163.Due to this structure, an aligning margin is enlarged, and thus a lightleakage may be blocked effectively.

The array panel for the liquid crystal display device according to thepresent invention is manufactured using four masks. The manufacturingprocess of the array panel will be described hereinafter in detail withreference to FIGS. 6A and 6B, FIGS. 7A to 7E, FIGS. 8A and 8B, and FIGS.4 and 5.

FIGS. 6A and 6B illustrate the step of manufacturing the array panelaccording to the present invention. FIG. 6A is a plane view showing themanufacturing step of the array panel, and FIG. 6B is a cross-sectionalview along line VIB-VIB of FIG. 6A.

In FIGS. 6A and 6B, a gate line 121, a gate electrode 122, a firstshielding pattern 124, and a second shielding pattern 125 are formed ona substrate 110 by depositing a metallic material and patterning themetallic material using the first mask. The substrate 110 is made of atransparent substrate such as a glass substrate and the metallicmaterial is made of a low resistive material. For example, the metallicmaterial includes chromium (Cr) or aluminum (Al), and thus the gate line121 may be formed of chromium, aluminum or an alloy of the chromium andthe aluminum.

Here, the gate line 121 is extended horizontally and the gate electrode122 is extended from the gate line 121. The first and second shieldingpatterns 124 and 125 are formed in the vertical direction, and thesecond shielding pattern 125 is connected to the gate line 121. Thefirst shielding pattern 124 has two projection parts facing toward thesecond shielding pattern 125 at both ends. The gate line 121 has aconcave part at the region corresponding to the gate electrode 122.

FIGS. 7A to 7E show other steps of manufacturing the array panelaccording to the present invention. FIG. 7A is a plane view of the stepof manufacturing the array panel according to the present invention, andFIGS. 7B to 7E are cross-sectional views along line VIIE-VIIE of FIG.7A.

In FIG. 7B, a gate insulating layer 130, an amorphous silicon layer 140and a doped amorphous silicon layer 150 are deposited on the substrate110 including the gate electrode 122 and the first shielding pattern 124in this order. A metal layer 160 is formed on the doped amorphoussilicon layer 150 by a sputtering method. Photo-resist patterns 191 and192 are then formed on the metal layer 160 by coating a photo-resistlayer, and exposing and developing the photo-resist layer. The firstphoto-resist pattern 191 is disposed at the first region, where sourceand drain electrodes are to be formed later. The second photo-resistpattern 192 is posited on the second region, where a channel between thesource and drain electrodes is to be formed later. The firstphoto-resist pattern 191 has a thickness greater than that of the secondphoto-resist pattern 192. There is no photo-resist pattern formedthereon except for the first and second regions.

A mask having a fine pattern is needed in order to form photo-resistpatterns having different thickness at one time as shown in FIG. 7B.FIG. 9 shows a part of the second mask according to the presentinvention.

In FIG. 9, a second mask 200 includes blocking patterns 261, 262 and 263and a fine pattern 264. The blocking patterns 261, 262 and 263correspond to a data line, a source electrode and a drain electrode tobe formed later. The fine pattern 264 corresponds to a channel to beformed later. The fine pattern 264 and the blocking patterns are formedto have inner and outer slits 265 a and 265 b at the channel area. Thefine pattern 264 and slits 265 a and 265 b have a width narrower than aresolution of the exposer.

Therefore, in the second region of FIG. 7B corresponding to the slits265 a and 265 b and the fine pattern 264 of the mask 200 of FIG. 9,since the exposed light has a low energy density by diffraction, thethickness of the second photo-resist pattern 192 becomes smaller thanthat of the first photo-resist pattern 191. The light transmittedthrough the slits 265 a and 265 b has a shape of spherical wave. Thus,the fine pattern 264 and the slits 265 a and 265 b are substantiallyformed in a “U” shape for the reproducibility of the pattern. The “U”shape of the pattern is substantially completely symmetrical.

In FIG. 9, a width “b” and “e” of the fine pattern 264 is 1.5 μm, andthe widths “a”, “c” and “d” of the slits 265 a and 265 b are 1.3 μm. Atthis time, the corner width “f” of the slit 265 b neighboring the drainelectrode is 1.1 μm that is narrower than those of the slits at “a”, “c”and “d” so that a channel width becomes constant.

As shown in FIG. 7C, a conductive layer 165, a doped semiconductor layer155, and semiconductor layer 141 are formed by etching the metal layer160, the doped amorphous silicon layer 150 and the amorphous siliconlayer 140 of FIG. 7B that are not covered with the photo-resist patterns191 and 192. Here, the semiconductor layer 141 becomes an active layer.

In FIG. 7D, the second photo-resist pattern 192 of FIG. 7C is removed byan ashing method using oxygen (02) gas. In this process, the firstphoto-resist pattern 191 is also removed. Accordingly, the thickness ofthe photo-resist pattern 191 may be reduced.

In FIG. 7E, a data line 161, a source electrode 162, a drain electrode163, and an ohmic contact layer 151 and 152 are formed by etching theexposed conductive layer 165 and the doped semiconductor layer 155 ofFIG. 7D under the exposed conductive layer 165. The remaining firstphoto-resist pattern 191 of FIG. 7D is removed. For example, the dataline 161, the source electrode 162, and the drain electrode 163 may beformed of molybdenum (Mo).

FIGS. 8A and 8B illustrate other step of forming a passivation layer ofthe array panel according to the present invention. FIG. 8A is a planeview showing the step of forming a passivation of the array panelaccording to the present invention, and FIG. 8B is a cross-sectionalview along line VIIIB-VIIIB of FIG. 8A.

As shown in FIGS. 8A and 8B, an insulating layer is deposited andpatterned using the third mask, so that a passivation layer 170 having acontact hole 171 is formed. The passivation layer 170 covers the dataline 161, the source electrode 162, and the drain electrode 163. And thecontact hole 171 exposes a part of the second part of the drainelectrode 163. The passivation layer 170 may be made of an inorganicmaterial, such as silicon oxide and silicon nitride, or an organicmaterial, such as benzocyclobutene (BCB).

Next, as shown in FIGS. 4 and 5, a transparent conductive material isdeposited and etched by a photolithography process using the fourthmask. A pixel electrode 181 is then formed on the passivation layer 170.The pixel electrode 181 may be made of a transparent conductive materialsuch as indium tin oxide (ITO). The pixel electrode 181 is connected tothe drain electrode 163 through the contact hole 171. The pixelelectrode 181 overlaps the gate line 121. Thus, the pixel electrode 181forms a storage capacitor with the gate line 121. Also, the pixelelectrode 181 overlaps the first shielding pattern 124, the secondshielding pattern 125, and the first part of the drain electrode 163.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the array panel for a liquidcrystal display device and the method of manufacturing the same of thepresent invention without departing from the spirit or scope of theinventions. Thus, it is intended that the present invention covers themodifications and variations of this invention provided they come withinthe scope of the appended claims and their equivalents.

1. An array panel for a liquid crystal display device, comprising: asubstrate; a gate line and a gate electrode on the substrate, whereinthe gate line is connected to the gate electrode; a gate insulatinglayer on the gate line and the gate electrode; an active layer on thegate insulating layer; an ohmic contact layer on the active layer; adata line, a source electrode, and a drain electrode on the ohmiccontact layer, wherein the data line, the source electrode, and thedrain electrode are formed of molybdenum; a passivation layer on thedata line and the source and drain electrodes; and a pixel electrode onthe passivation layer, wherein the ohmic contact layer has the sameshape as the data line, the source electrode, and the drain electrode,and the active layer has the same shape as the data line, the sourceelectrode, and the drain electrode except for a channel area between thesource electrode and the drain electrode, and the channel area has a “U”shape.
 2. The panel according to claim 1, further comprising a firstshielding pattern formed of the same material as the gate line and beingparallel to the data line.
 3. The panel according to claim 2, whereinthe first shielding pattern overlaps at least a portion of the pixelelectrode.
 4. The panel according to claim 2, wherein the firstshielding pattern has a plurality of projecting parts overlapping thedata line at both ends.
 5. The panel according to claim 2, furthercomprising a second shielding pattern parallel to the first shieldingpattern.
 6. The panel according to claim 5, wherein the second shieldingpattern overlaps at least a portion of the pixel electrode.
 7. The panelaccording to claim 5, wherein the second shielding pattern is connectedto the gate line.
 8. The panel according to claim 1, wherein the drainelectrode includes a first part parallel to the gate line and a secondpart extended from the first part.
 9. The panel according to claim 8,wherein the first part overlaps at least a portion of the pixelelectrode.
 10. The panel according to claim 8, wherein the second parthas a plurality of protrusions and is exposed by a contact hole.
 11. Thepanel according to claim 1, wherein the pixel electrode overlaps atleast a portion of the gate electrode.
 12. The panel according to claim1, wherein the “U” shape is substantially completely symmetrical.
 13. Amethod of manufacturing an array panel for a liquid crystal displaydevice, comprising: forming a gate line and a gate electrode on asubstrate; forming a gate insulating layer on the gate line and the gateelectrode; forming an active layer on the gate insulating layer; formingohmic contact layer on the active layer; forming a data line, a sourceelectrode, and a drain electrode on the ohmic contact layer, wherein thedata line, the source electrode, and the drain electrode are formed ofmolybdenum; forming a passivation layer on the data line, the sourceelectrode, and the drain electrode; and forming a pixel electrode on thepassivation layer, wherein the ohmic contact layer has the same shape asthe data line, the source electrode, and the drain electrode, and theactive layer has the same shape as the data line, the source electrode,and the drain electrode except for a channel area between the sourceelectrode and the drain electrode, and the channel area has a “U” shape.14. The method according to claim 13, wherein the forming the gate lineincludes forming a first shielding pattern formed of the same materialas the gate line and parallel to the data line.
 15. The method accordingto claim 13, wherein the first shielding pattern overlaps at least aportion of the pixel electrode.
 16. The method according to claim 15,wherein the first shielding pattern has a plurality of projection partsoverlapping the data line at both ends.
 17. The method according toclaim 15, wherein the forming the gate line includes forming a secondshielding pattern parallel to the first shielding pattern.
 18. Themethod according to claim 17, wherein the second shielding patternoverlaps at least a portion of the pixel electrode.
 19. The methodaccording to claim 18, wherein the second-shielding pattern is connectedto the gate line.
 20. The method according to claim 13, wherein thedrain electrode includes a first part parallel to the gate line and asecond part extended from the first part.
 21. The method according toclaim 20, wherein the first part of the drain electrode overlaps atleast a portion of the pixel electrode.
 22. The method according toclaim 20, wherein the second part has a plurality of protrusions and isexposed by a contact hole.
 23. The method according to claim 13, whereinthe pixel electrode overlaps at least a portion of the gate electrode.24. The method according to claim 13, wherein the “U” shape issubstantially completely symmetrical.